Cinderella
by I Took the One Less Travelled
Summary: Crossover with Avengers movie. In which Dawn falls through a portal to New York as Tony puts the nuclear bomb into the portal. Clint Barton/Dawn Summers, Tony Stark/Pepper Potts, Jane Foster/Thor, mentions of Angel/Buffy Summers/Spike threesome, more pairings to come. badass, demon hunting watcher!Dawn


Disclaimer: All recognizable characters, scenes or events from the Avengers belong to Marvel, and Buffy characters, scenes and events belong to Joss Whedon and Mutant Enemy.

Cinderella

Prologue

I don't wanna be like Cinderella  
Sitting in a dark old dusty cellar  
Waiting for somebody to come and set me free  
I don't wanna be like Snow White waiting  
For a handsome prince to come and save me  
On a horse in white unless we're riding side by side  
Don't wanna depend on no one else  
I'd rather rescue myself

Dawn Summers eyed the demon nest in front of her and frowned. It wasn't very often anymore that she couldn't identify a demon species when she saw one, but she had no idea about his particular demon breed, and it unsettled her.

Theoretically, it would be smart for her to call for a couple of Slayers to back her up—decent fighter she might be, but she didn't have super-strength. But Dawn didn't often practice street smarts, and it showed—she shot a crossbow bolt into the nest and sent the demons into a panic, rolling out from behind the pillar that she was hiding with to start kicking.

She was winning, too. She had the element of surprise on her side, and Buffy had made sure that she was a very talented fighter before she had let her anywhere near the council, and it showed. She twisted when a demon grabbed her by the ankle and managed to wrap her thigh around its head and crack its neck. She was dropped into a heap on the cave floor, but rolled back to her feet instantly.

Maybe her fighting style was dirty, but when she was up against creatures that were so much stronger than her, and in this case very much outnumbered her, she didn't have a choice.

Then one of them got her in the stomach with its sceptre thing, and Dawn started to panic. It was the last one alive, and she killed it shortly afterward, but nobody was quite sure what would happen when large quantities of her blood were spilled, but Willow had determined that, contrary to what they had believed after Glory, the key was not gone.

Of course she had bled before, but she had never been stabbed.

And, sadly, it turned out that she was right to worry—the swirling portal that formed where copious amounts of her blood dripped to the cave floor seemed to blossom like a flower, green and white striking through the air. Dawn scrambled back, watching it.

Was it going to behave like the last portal that she had opened this way, or was it going to close harmlessly and be on its way?

Absently, she checked the knife wound carefully, determining that it was fairly deep, but nothing truly lethal, as long as she got it to stop bleeding. She wadded up her sweater and pressed it to her stomach before turning her attention back to the portal.

It had opened on something, that was for sure. In fact, it looked like it had opened on deep space. Blackness pinpointed with star pinpricks in the background, from what she could see. Then the power started whipping out of the portal. She knew this—this was when the portal started to destroy the walls between the dimensions.

And this time, there was no Buffy to jump into it for her.

Dawn swallowed, took a moment to wish that she could leave some sort of message for her sister, and did what she needed to do. She hurled herself forward into the portal, expecting the light to envelope her and run all over her body—she still had nightmares of what Buffy had looked like, wrapped in this portal. Instead, she went through it. And it closed behind her, and she was in space.

There wasn't oxygen up here, and she immediately felt her lungs close up because of the pressure. And she was falling-falling—and then she could breathe again. It had happened so fast, she wasn't sure what was going on, but she had fallen through _another_ portal, it seemed, one that had led her back to earth. Back to what appeared to be New York. An unfortunate several thousand miles _above_ New York, but she could breathe again.

Then she looked up. There was some sort of robot falling above her. Hot rod red and gold adorned the metal plating. Dawn stared incredulously. Maybe she had already died? Or was at least unconscious, because this had to be some sort of hallucination. She was plummeting to earth, faster than she knew she could stop. Thankfully, she had been resigned to her death earlier, and wasn't too surprised to see it coming now.

And then it didn't, because she and the robot suit thing were grabbed out of the sky by a giant green monster. Dawn was too shocked to scream. The green thing cradled the metal guy in the crook of his arm, and her gently against his chest, and used one hand against a nearby skyscraper to lessen his momentum.

He dropped her and sent her rolling away from him, and held the metal guy cradled on top of him before flipping him over onto the ground and standing up.

Two other people converged on them. The guy dressed in blue spandex ripped the faceplate off of the metal suit, revealing an actual, honest-to-God _person_ underneath. Dawn scrambled backwards and pressed her sweater more firmly to her still bleeding stomach.

The other man was a massive blonde guy that looked like he belonged on a California beach, except for the fact that he was wearing renaissance worthy chain mail and dangling a metal hammer that looked very similar to Buffy's troll hammer from his huge fist.

While the guy in blue spandex tried to rouse the one in the metal suit, big-massive-blond-guy knelt next to Dawn.

"Are you well, milady?" he asked placing one hand on the small of her back to help prop her up. "You seem to have fallen into this world by accident, much as I have. I never would have expected the Key to be in such a form as this."

She stared at him for a moment.

"I am Thor, son of Odin and prince of Asgard," he offered, extending a hand to help her up.

"Dawn Summers," she replied weakly. She pulled the sweater from her abdomen to eye underneath it, only to find that the wound was gone. "Okay, that's freaky."

She took Thor's hand and allowed him to boost her to her feet, leaning on him shakily.

Then the green monster roared. Dawn almost fell over again, and would have if Thor hadn't caught her. The man in the metal suit jerked awake.

"What happened? Please, tell me that nobody kissed me."

"We won," blue spandex said, in a voice that was deep and heroish and somehow made Dawn think about her mother's apple pie. Looking more closely at him, she realized that his outfit appeared to be covered in the American flag.

"Who's _she_?"

"We have no idea, I was just about to ask her that," blue spandex said.

"The key," Thor said at the same time. "The key made human. Please, Lady Dawn, if you would do me the honour of accompanying me to see my brother? That, I think will be what finally removes the poison of revenge from inside of him."

Dawn nodded shakily.

"What does that _mean_, Thor?"

"Captain, the key is beyond mortal comprehension. What it is truly capable of is beyond even my comprehension, perhaps even beyond Loki's."

"Does anyone have a phone that I could use to call my sister?" Dawn finally asked. "She's probably freaking out by now."

The metal guy produced a Bluetooth earpiece. "It's voice activated—just tell it what number you want to call, and it'll dial."

"Thank you," Dawn said.

She clipped the earpiece onto her ear and rattled her sister's cell number into it. The number dialled and then— a cool, robotic female voice answered, informing her that the number that she had called could not be completed as dialled. She pressed the hang up button on the Bluetooth and immediately rattled off the council's emergency line—and connected with a pizza place.

"I'm in another dimension," Dawn said, dazed. "God, I'm in another dimension, and Willow won't even know what happened to me or where to look. I'll just have disappeared. Oh, God," she said, choking back the lump in her throat. She was strong, she was confident. Faith Lehane and William the Bloody had taught her how to fight. She was _not going to cry_. She despised crying women who just sat around and waited for someone else to rescue them. This time, she was on her own, and she was going to rescue herself.

She hoped.

Alien invasion. After Dawn had established that she was in an alternate dimension, she was told that New York had just witnessed an alien invasion.

The man in the metal suit was Tony Stark, and was, as far as she could tell, normal outside of the metal. The guy in the blue spandex was Steve Rogers, or Captain America, and he had been dosed with some kind of chemical in World War II to make him stronger and faster than humans. The green guy, Hulk, was apparently the alter ego of a scientist named Bruce Banner, who had dosed himself with gamma radiation to replicate the serum that had made Steve what he was, and failed spectacularly. Thor was the honest-to-God Norse God of Thunder, which honestly didn't surprise Dawn at all. He had the same vibe to him that Glory had.

They were joined on the way up the elevator of what Tony called his 'baby' by a very good-looking guy in Kevlar with a bow and arrow, who introduced himself as Agent Clint Barton.

They ran into the red-haired woman once they reached the top of the tower—Agent Natasha Romanoff. And Loki, the Norse God of Mischief, who dug himself out of a hole in the ground before even realizing that they were there. And then he asked for a drink. Loki, who had apparently started the whole alien invasion thing in the first place.

Loki, who had gone still and silent the second that he laid eyes on Dawn, when Thor, who seemed overly protective of her, had pushed her into his view.

"Look, brother," he said, loud voice rumbling gently.

"So _that's_ where it got to," Loki drawled.

And to think that Steve had wanted to leave her down in the city below when they had gone to confront Loki, but Thor had insisted.

Loki unfurled himself from the step and stood carefully. Clint pointed his bow at him, and Loki moved slowly towards Dawn.

"What's your name, little one?"

"Dawn," she answered, mesmerized.

"And how does the Key, of all things, end up in the form of a little girl like you? Not mortal, oh, not anymore—"

"What?"

"You didn't tell her, _brother_?"

"She just got here," Thor said. "I haven't had the chance yet."

"Let me spare you the trouble. You may have been mortal wherever you were before, child, but you aren't now." He pressed his hand under her chin and forced it up to meet her eyes. "The key is an immortal being, I'm sure that your days as a mortal were numbered anyway. But you are not anymore mortal than Thor or I."

Dawn jerked away. Now _she_ was immortal? It had been established that Slayers didn't age, and they had gotten killed so often before now that no one had ever discovered it. But someone had realized that Buffy looked about eighteen and didn't appear to be changing, and Faith as well. That was fine for Buffy—Angel and Spike were vampires, after all, if vampires with souls. But _Dawn_ didn't want to be immortal!

"No!"

"Oh, yes," Loki said, clearly enjoying this. At least before Clint sent an arrow at his head. Loki smoothly caught it in one hand without turning around. "I wouldn't, Barton."

"Your army's gone, Loki. And I owe you an arrow through the eyesocket."

"Loki, leave the girl be," Thor commanded. "Captain?"

"Thor, get the Tessaract, we'll pack it up for you to take to Odin. Do you have a way to get back to Asgard?"

"Oh, he has two, now," Loki said, smirking.

Dawn smacked him across the face. She had always had a bit of an itchy trigger finger.

**Welcome to my latest story, a crossover with the Avengers movie and Buffy the Vampire Slayer- AKA, another one of those stories where Dawn falls into a portal to another world. In this case, she fell into space where the Chituari were making camp, right after Tony launched a nuke at them, and fell back through the portal to earth with him. Title and opening quote both come from the song Cinderella by Play. Future pairings- Tony Stark/Pepper Potts, Jane Foster/Thor and Clint Barton/Dawn Summers. Dawn is twenty-five as this fic is taking place. **


End file.
